arizona cardinals, buffalo bills, chicago bears, cleveland browns, kansas city chiefs, philadelphia eagles, and san diego chargers all fired their coaches a day after the regular season ended. five teams also axed their general managers. those are some of the day's major stories. now, back to ray. >> suarez: next, secretary of state hillary clinton was hospitalized yesterday after doctors discovered she had a blood clot. few details of her condition were initially released, but late today her doctors said the clot was located in a vein between her skull and brain. they stressed she did not suffer a stroke and is making excellent progress. dr. gholam motamedi, a neurologist at medstar georgetown university hospital, is here to walk us through the known risks and treatments for blood clots. i guess, doctor to start at the very beginning, what is a blood clot. >> blood normally has a tendency to coagulate or clot. if you take the blood out of the system, out of the circulatory system t will clot. if you are, let's say, laying down in a hospital, typically in a hospitalization, without movemen